Process of extracting nicotine from tobacco



Aug. 23, 1938. J. B. GARNER I 3 PROCESS OF EXTRACTING NIGOTINE FROM TOBACCO Fild July 11, 1936 LIQUID Amara 0200.5 AMMONIA {Iv/ ET VENT LINE EXTRACZTOR CONDENSER I: O TIA/E L) TAET COMPRESS O1 AMMONIA Race 1 v 634.3 INLET ACCUMl/LA T/IVG 7'4/VK JAnEs IBGA'RNER Patented Aug. 23, 1938 I I 2,128,043

UNITED STATES PATENT orrics 2,128,043 PROCESSOF EXTRACTING NICOTINE FROM TOBACCO James B. Garner, Mount Lebanon, Pa., assignor to Hope Natural Gas Company, a corporation of West Virginia Application July 11, 1936, Serial No. 90,071 10 Claims. (01.87-28) This invention relates to improvements in the normally gaseous hydrocarbons just .mentioned extraction of tobacco for the preparation of nicoor their admixtures, where the context so pertine, nicotine extracts, tobacco wax or resins and mits. other products, while leaving the tobacco itself Inthe accompanying drawing, the single figure in condition for commercial use. is a diagrammatic view of one form of extraction. 5

A particular object of the invention is to preapparatus. The process will be described in conpare a denicotinized tobacco suitable for making nection with the recovery of nicotine from tomild smoking tobacco and similar products. bacco leaves or tobacco residues.

A further object of the invention is to prepare In carrying out the invention, tobacco contain- -1G a solution of nicotine in a volatile hydrocarbon, ingapproximately -25% by weight of water, 10

which can be used as such under its own vapor as commonly encountered in commercial practice,

pressure for insecticidal or germicidal purposes, is treated with anhydrous liquid ammonia to i or the like. liberate all the nicotine from its salts, and then Another object of the invention is to prepare extracted with as many consecutive amounts of 5 nicotine concentrates adapted for use in comliquid butane as is indicated to reduce the nicopounding with solvents and other ingredients for tine content to the desired amount. It is genthe manufacture of insecticides and germicides. erally desirable to place the tobacco, loosely but These and other objects of the invention which with slight pressure into a bag 1, insert this bag will be apparent as the description proceeds, are into an extractor 2, and immerse the bag in the obtained by treating the tobacco with a material liquid butane at substantially room temperature 20 adapted to liberate nicotine from its salts. This (Mi-90 F., corresponding to 330 pounds pressure material is preferably anhydrous liquid ammonia, per square inch). The butane is run into the though other alkali forming substances may be extractor through a line 3 in which there is a used. The tobacco is then extracted with a valve 3a. Liquid anhydrous ammoniais then in- .25 liquefied normally gaseous hydrocarbon, especi troduced gradually so that no appreciable rise in ally liquid normal butane. pressure ensues, througha line 4 in which there Nicotine is now manufactured on a rather exis a valve to. The ammonia reacts at it enters tcnsive scale from inferior grades of tobacco, tothe mixture, usually until four to eight times bacco stems and trimmings. The nicotine thus the amount calculated to correspond to the nicomade finds a ready market as an insecticide and tine present has n a d F this p nt n 30 germicide. The tobacco residue, however, in the there is a continuous rise in pressure which does usual commercial manufacture of nicotine has not recede with elaps time. and e nflo f littleor no value. ammonia is stopped.

It is known that nicotine, which is a liquid The mixture is then left to react by circulation di-acid base, may be liberated from its salts, such of the liquid for several hours until a sufficient 35 as those of citric, malic, and oxalic acids, in concentration of the extractives is obtained in the which it occurs in tobacco, by treatment with liquid. The circulation takes place by means of anhydrous liquid ammonia. This reagent does a pump 5, a bottom draw-off line 6 having a valve not discolor the tobacco if properly applied. Ac- 1, and a top supply line 8 having a valve 9, both 40 cording to the present invention, the released nicthe valves being open. A storage tank I0 is con- 40 otine is then extracted with a. liquefied normally 'nected with the pump by means of a line H havgaseous hydrocarbon. This may be liquid proing a valve l2. pane, liquid normal butane, isobutane, butyiene, After a test of the liquid, run off through the isobutylene or mixtures of these hydrocarbons, valved sample line l3, shows a substantially com- -15 or any other liquefied normally gaseous hydrooarpleted reaction (the desired point varying with bons or mixtures thereof which will dissolve nicoseveral operating conditions and the purposes in tine. Small amounts of the more volatile and less mind), the liquid is drawn off as completely as volatile hydrocarbons such as ethane and penpossible and replaced by successive fresh amounts tane, may be present without interfering with of butane. Each batch of butane is circulated for the process. Liquid normal butane, however, is a time and the extraction is continued until the 50 the preferred solvent in most cases. It can also nicotine content of the leaves has been reduced be obtained most economically in large quantities to the desired amount. The various batches of at areasonable price. butane are accumulated in the tank it, from In the following description and claims the which they are run by line it, pump 5, and line term butane" is intended to include any of the i4 (valves 1 and 9 being closed and valves i2 and.

l open) into a still it. A vapor line H, having a valve it leads from the top of extractor 2, conmeeting with the vapor line from still l6. If desired, the separate charges of butane may be distilled by drawing them oif individually through the sample line l3 to a suitable still. The combined or successive amounts of butane are distilled to recover the components, namely, butane, ammonia, and extractives. The extraction may be carried out continuously without affecting the purpose of the invention.

The extractives are drawn off, usually as a liquid containing some residual butane, and the nicotine is separated subsequently from the waxes. etc. if a pure grade of nicotine is desired. The vapor line from the still is designated l9 and in it there is a valve 20. The mixture of butane and ammonia withdrawn passes first to a compressor 21 and thence through line 22 to a condenser 23. 'A valved vent line '26 is provided on line I! and a valved vent line 25 on line 23. From the condenser the butane and ammonia pass. through line 26 into a receiver 2l,-from which they are returned to tank ill through line 28. The nicotine extractives are removed from the still is in which they have been freed from butane and ammonia, into an accumulator 86a and thence to a place of disposal through line llib. The still is shown as heated by means oi a hot water circulating systern including a heater 22 and circulating pipes 30. and Si.

In order to clear the extractor of residual solvents, dry air, nitrogen, carbon dioxid, or other inert gas may be passed under pressure through a line 32, sample line it and draw-off line 6 into extractor 2. 'This is a convenient way of accomplishing the result but other methods, such as vacuum evaporation, may be adopted.

In order to retain the leaves in their natural condition to the maximum extent, it is desirable to control rather careiully the content of moisture during the extraction and solvent removal periods. In the extracting period the water content of the tobacco should be between 10 and 25% by weight. If the tobacco leaves are too dry they are too brittle for handling and the extraction proceeds too slowly. A higher moisture content than 25% has been found unnecessary and it tends to discolor the leaves. In the period for removal of residual ammonia and solvent, if a gas is used, its moisture content should be approximately between 55 and 65% of saturation at the prevailing temperature.

The preferred way of conducting the extraction is to pile the leaves in a filter cloth bag in a pressure vessel. The treating liquids are then circulated continually through the mass of leaves. Any small fragments of tobacco are thus retained inside of the bag and hence do not in any way collect in or stop flow of liquids through piping and pump. The invention, however, is not limited to any special form of extraction equipment or arrangement therein.

The nicotine content of tobacco may vary from about 2.5% to 2.8% by weight of the dry leaves, under usual conditions. The ammonia used in this process should range in concentration from about 4-8 times the calculated amount necessary to set the nicotine free from its combination with organic or other acids. Less than four equivalents is inadequate to effect practically complete removal of nicotine, morethan eight equivalents is wasteful and uneconomical. As high as 17 equivalents have been used but with no better results than when eight equivalents are used.

, leaves; hence, when denicotinized tobacco is to be manufactured, anhydrous ammonia must be used. When the production of nicotine alone is the end in view, butane plus aqueous ammonia or other alkali adapted to liberate nicotine may be used and in this case any suitable source of nicotine may be used. The butane should be present in convenient excess so as to insure the rapid ex traction of substantially all the nicotine. The concentration in the residual tobacco can be reduced in this way to about 0.10% or less.

It will be understood that some of the tobacco wax and resins are dissolved along with the nicotine and are to be separated from it at a'later stage, as by solution and precipitation, if the pure product is desired. 1

The butane solution of nicotine and tobacco waxes and resins is treated for the separation of the extracted materials, preferably as described, by distilling off the butane at relatively low temperature, not necessarily higher than 100 F., although vacuum evaporation, with or without fractional precipitation of the solutes, may be used. The distillation may be stopped at a point where the solution contains a suitable insecticidal or germicidal concentration of nicotine and the product used as such. It can be conveniently applied from devices of the kind which eject a material carried by a. liquefied normally gaseous sub-' may amount to as much as 6-8% by weight of the tobacco used. A lesser quantity of wax may be obtained if desired. Tobacco wax or resin is dark brown in color, burns with the production of acrid fumes, and has a strong odor resembling that of an old pipe. The wax has been found to be composed of a weak acid (about 0.94% by weight), a stronger acid (about 1.27%), and a neutral substance (about 97.79%).

The extract may be treated in various ways for the recovery of the nicotine and wax, for example, by dissolving the mass in ether or other suitable solvent and adding an-excess of dilute hydrochloric acid to remove the nicotine as the hydrochloride. Then a 2% solution of sodium bicarbonate isadded to remove the stronger wax acid. Next 2% sodium hydroxid solution is applied to separate the weaker wax acid. The remaining solution is evaporated to recover the neutral portion of the extract.

These products may be used for various purposes. The nicotine may be used as such or toather with the tobacco waxes as insecticides and germicides. The waxes or portions thereof may be returned to the residual tobacco leaves and also to untreated tobacco leaves to impart thereto desirable flavors. The value of inferior grades .of tobacco may thus be enhanced.

As noted, the tobacco leaves are not impaired and can be used with special advantage for making mild smoking tobacco, cigarettes, or other any solvent, other than hydrocarbon solvents, providing it has an appreciable solvent action on nicotine and does not react with the ammonia or other alkali used; (2) that other alkalies, such as the aliphatic gaseous amines, may be used in place of ammonia; (3) that aqueous solutions of alkalies, such as sodium, potassium, calcium, strontium, barium, magnesium hydroxids, their xcarbonates, or the ethanolamines, may be used to liberate nicotine when their effect upon the tobacco is no disadvantage.

Various other changes and alternative procedures. may be adopted within the scope of the appended claims in which it is my intention to claim all novelty inherent in the invention as broadly as the prior art permits.

I claim:

1. Process of extracting nicotine, comprising freeing the nicotineirom its salts by means of an acid neutralizing reagent, and dissolving it in a liquefied, normally gaseous hydrocarbon.

2. Process of extracting nicotine from tobacco, comprising freeing the nicotine from its salts by means of an acid neutralizing reagent, and dissolving the liberated nicotine in liquid butane.

3. Process according to claim 2 in which liquid normal butane is used.

4. "Process according to claim 2 in which an al' kali is used to liberate the nicotine.

5. Process according to claim 2 in which liquid anhydrous ammonia is used to liberate the nicotine from its salts.

6. Process of extracting nicotine from tobacco, comprising treating the tobacco with liquid ana liquefied, normally gaseous hydrocarbon.

8. Process of extracting nicotine from tobacco by liberating the nicotine from its salts by neutralization with an alkaline reacting substance selected from the class of aqueous solutions of alkalies of sodium, potassium, calcium, strontium,

barium and magnesium and the ethanolamines, and extracting the liberated nicotine with a liquefled, normally gaseous hydrocarbon.

9. Method of preparing nicotine and tobacco waxes comprising extracting these materials from tobacco by liberating the nicotine from its salts by means of an acid neutralizing reagent and dissolving in liquid butane, removing the liquid butane containing the nicotine and tobacco waxes from tobacco, separating the liquid butane from the nicotine and tobacco waxes, treating the residue with a suitable solvent to dissolve the nicotine and tobacco waxes, and then separating the nicotine from the resulting solution.

10. Method according to claim 9, comprising selectively separating the acidic components of the tobacco wax from the solution in a suitable solvent after removal of the nicotine by treatment with alkalies of progressively increasing strength.

' JAMES B. GARNER. 

